(Reuters) -Activist investment firm Engine Capital wants Lyft to consider strategic alternatives, including a sale, piling more pressure in its proxy battle against the ride-sharing platform.

The investor, which owns about 1% of Lyft, also accused the company's board of lacking financial expertise, saying seven of its 10 members did not have much prior experience as directors of public companies.

Earlier this month, Engine nominated two directors to the board of Lyft and said its attempts to engage with the ride-hailing company's leadership were rebuffed.

Engine said on Tuesday that its director nominees would encourage Lyft's board to explore strategic alternatives that could lead to the sale of the company as a whole or in parts.

It proposed that Lyft execute a $750 million accelerated share buyback plan to counterbalance stock underperformance and signal confidence to the market.

Lyft's cash balance and short-term investments totaled about $2 billion at the end of last year.

In response, Lyft said it was confident in its prospects, citing the company's recent entry into European markets through its buyout of Freenow and an inaugural share buyback program announced earlier this year.

The company's shares have fallen about 83% since its initial public offering in 2019, compared with sharp gains at larger rival Uber Technologies.

Lyft has a market capitalization of about $5.2 billion, while Uber is valued at $164 billion.

Engine also criticized Lyft's dual-class share structure, which concentrates 30% of voting power in the hands of its co-founders, who now hold about 2.3% of the company's equity.

The activist called for the board to eliminate staggered elections and address excessive equity dilution, which it said has averaged nearly 8% annually, undermining shareholder value.

(Reporting by Akash Sriram in Bengaluru; Editing by Shilpi Majumdar and Anil D'Silva)