Nov 1 (Reuters) - Eli Lilly and Co on Tuesday forecast its annual profit and revenue below estimates, as a stronger dollar piled more pressure on the drugmaker struggling with lower insulin prices and generic competition for its cancer drug.

The company's shares fell 2.6% on Tuesday as a forecast cut for the third time this year overshadowed strong performance by its newly approved diabetes drug.

Eli Lilly now expects adjusted full-year earnings of $7.70 to $7.85 per share, compared to its prior forecast of $7.90 to $8.05 and below analysts' expectations of $7.97.

The drugmaker also trimmed its full-year revenue forecast, citing a $300 million hit to its revenue from the strong dollar. Lilly now sees revenue in the range of $28.5 billion to $29 billion, below analysts' estimates of $28.76 billion at mid-point.

Multinational companies such as Abbott Laboratories and Johnson & Johnson have been hit by the dollar's strength against a basket of currencies.

Last month, J&J said a stronger dollar will reduce its 2023 adjusted earnings by between 40 cents and 45 cents. Lilly flagged a total impact of about $1 billion from the strong dollar for the full year.

The company posted better-than-expected results for the third quarter, as demand for its recently approved diabetes drug, Mounjaro, helped counter declining sales of its diabetes and cancer treatments.

Mohit Bansal, an analyst at Wells Fargo, said a second straight quarter of strong Mounjaro sales is an encouraging sign as the drug's launch has been promotion driven.

Investors are closely focused on Mounjaro's uptake as it is expected to have blockbuster potential, especially if approved as a treatment for obesity.

Third-quarter sales of the diabetes drug was $187.3 million, with more than half coming from the United States, and easily beating estimates of $81 million. (Reporting by Bhanvi Satija and Leroy Leo in Bengaluru; Editing by Sriraj Kalluvila and Maju Samuel)