Zynga Inc reported better-than-expected fourth-quarter revenue, but the developer of social media games like FarmVille failed to add new daily players compared with last quarter.

Zynga said on Tuesday in its first financial results as a public company that it had fourth-quarter revenue of $311.2 million. Analysts, on average, had expected revenue of $301.08 million, according to Thomson Reuters I/B/E/S.

It had a net loss of $435 million, or $1.22 cents a share, compared with net income of $42 million, or 5 cents share, a year ago. Excluding items, Zynga's earnings per share of 5 cents beat analysts' average estimate of 3 cents per share.

Zynga said in a regulatory filing that its daily active users were 54 million in the three months ended December 31, flat from the previous quarter.

The fact that Zynga is not adding new players at a high click each quarter is a concern to investors, analysts said.

They have to work harder to get existing traffic to pay more. That's a challenging proposition, said Sterne Agee analyst Arvind Bhatia.

Zynga's shares were trading at $13.93 after hours, after closing at $14.35 on the Nasdaq.

Zynga, whose games are popular on Facebook, raised $1 billion in an IPO in mid-December.

(Reporting By Liana B. Baker in New York, Additional reporting by Gerry Shih in San Francisco, editing by Matthew Lewis)