Shares of Safeguard Scientifics rose Thursday, closing up 2.5 percent at $12.50 a share, after the Radnor-based tech investment company reported higher 2017 losses and chief executive Stephen Zarrilli outlined his plans for future profits, under pressure from investors who want swifter action.

Zarrilli says he expects it will take "three to five years" to sell all of Safeguard's current investments in 25 tech firms at optimal prices, and cash in federal tax benefits from past losses.

The CEO has faced dissent from restive shareholders including Main Line investor Darren Wallis and Ira Lubert, a former Safeguard executive who with his Philadelphia partners now manages $18 billion in real estate and private investments.

In letters to Safeguard's board, Wallis and his allies have said Safeguard can sell its assets quicker, and save on administrative costs. Wallis and Lubert have threatened to run for Safeguard's board against candidates loyal to Zarrilli if the company doesn't expedite the process and reduce its staff beyond what the company promised earlier this winter.

Both sides have agreed the company should  wind down its investments in tech companies.

In a meeting with shareholders Thursday, Zarrilli reiterated plans to maintain a full-time investment staff, now numbering 16, at a cost of over $10 million a year, to help boost the companies until they are ready to sell. Over time, Zarrilli says Safeguard can cash in tax benefits from years of losses, cancelling federal taxes it would otherwise owe when it sells tech-company shares.

The Zarrilli-allied board last week changed its rules, making it tougher for outside investors to buy more than 5 percent of Safeguard's own shares without management permission. Zarrilli told investors this was necessary to preserve the tax benefits from over-hasty asset sales. "Much work lies ahead to identify the right exit opportunities," he told investors.

Wallis and his allies have said they could more than double Safeguard's value from its current share price while cutting administrative costs. They have seen the board's recent actions as a power grab, designed to help Zarrilli and his management allies keep spending millions a year on their own compensation at shareholders' expense.

In a conference call with investors Thursday, analysts at Stifel & Co. and Baird & Co. complained to Zarrilli that the board's recent moves could depress Safeguard share prices by keeping large investors from buying shares.

Among Safeguard's more promising investments, Zarrilli cited MediaMath, a digital advertising technology company founded by Joe Zawadzki in 2009, that may yet return more than the $25.5 million Safeguard has invested over the last nine years.

Zarrilli added that Safeguard invested $14.5 million more in financial technology developer Transactis since 2014, for a 24 percent stake; this investment is carried on Safeguard's books at a discounted value of $9.1 million, but Zarrilli said it could be worth more if founder Joe Proto's growth projections prove accurate.

He also said health tech developer Syapse is likely to grow this year, after Safeguard invested $2.3 million and other companies invested more than $27 million. UPDATE 3/2/18: Syapse, a "precision medicine" cancer treatments developer based in San Francisco, recently said it plans to double the workforce at its four-year-old Philadephia-area satellite office — in Radnor, Pa., near Safeguard headquarters — boosting headcount from 15 to around 30 "software engineers, account managers, operations support" and other positions.

"The Philadelphia region is a major center of both technical talent and leading healthcare organizations, which makes it an ideal location for high-growth health IT companies," said Michael Italia, senior director of product development and the company's top Philadelphia-based officer. "We have been fortunate to attract some tremendous talent in the area," Italia said in a statement.