Aug 5 (Reuters) - Corteva Inc (CTVA.N) on Thursday raised its net sales forecast for the year after strong demand for crop protection products such as herbicides and insecticides helped the agricultural company beat estimates for the second quarter. Corteva also announced a new $1.5 billion share repurchase program, in addition to a $1 billion buyback announced in 2019, which the company expects to complete by the end of 2021. The company"s shares rose 3.7% to $43.00 in extended trade. Last month, it increased its common stock dividend by 7.7% to 14 cents per share. The company, spun off in 2019 after a merger of Dow Chemical and Dupont, has laid off employees and retired some assets to cut costs. Last month, it said Chief Executive Officer James Collins Jr will retire, months after activist investor Starboard Value LP sought to oust him. read more Corteva forecast 2021 net sales between $15.2 billion and $15.4 billion, versus an earlier estimate of $14.6 billion to $14.8 billion. Analysts were expecting $14.82 billion, according to Refinitiv IBES. Net sales rose 8.4% to $5.63 billion in the second quarter, surpassing an estimate of $5.33 billion, while total crop protection sales jumped about 12% to $1.85 billion due to demand for its new products including Arylex herbicide and Pyraxalt insecticide. Seed sales rose 7% to $3.78 billion in the quarter thanks to increased soybean acreage in North America and higher volumes on the back of more normalized delivery timing in the region. The Wilmington, Delaware-based company said operating earnings per share rose to $1.04 billion, or $1.40 per share, in the quarter ended June 30, from $944 million, or $1.26 per share, last year. Analysts on average had expected a profit of $1.26 per share.