The ASX dividend share Washington H. Soul Pattinson and Co. Ltd (ASX: SOL) reported its FY25 half-year result last week. The report included everything I wanted to see.

For me, it's one of the leading options on the ASX for passive income. It may not have the biggest dividend yield, but I think the payout track record and long-term growth more than account for that.

Thanks to the progress I saw in the report, let me explain why this diversified investment house is one of my top picks for dividends on the ASX.

Another impressive milestone for the dividend

In the result, the business reported that regular net profit after tax (NPAT) grew by 18% to $284.8 million, and cash flow per share increased by 8.2%. This helped fund a 10% increase of the interim dividend to 44 cents per share. The business has now achieved 25 years of consecutive dividend growth.

Since 2000, the ordinary dividend has increased at a compound annual growth rate (CAGR) of 9.8%, which excludes $1.05 of special dividends per share over that time period.

While dividend growth is not guaranteed, I like that it's one of the company's main goals. Soul Patts invests in assets it thinks can help deliver the cash flow to continue growing the dividend.

The last two declared dividends by the ASX dividend share amount to a grossed-up dividend yield of 4.1%, including franking credits.

Further strengthening of the non-ASX share parts of the portfolio

The business has been deliberately allocating money towards assets that offer growth potential but aren't necessarily larger ASX shares.

It has been allocating money towards both its credit and private equity portfolios.

Around 28% of its assets are now in private markets, which is a useful position considering Soul Patts faces less competition for buying private assets than public assets.

Some of its private businesses include Ampcontrol (electrification), Aquatic Achievers (swimming schools), an agricultural portfolio, and Ironbark (financial services). Impressively, over the past three years, Ironbark has grown its operating profit (EBITDA) at a CAGR of 42%, and Aquatic Achievers has grown its EBITDA at a CAGR of 63%.

The ASX dividend share invested another $84 million in its private equity portfolio in the first half.

Strong balance sheet

While I hope to see strong capital growth every year, that won't always happen. Soul Patts revealed that at the end of the first half of FY25, its pre-tax net asset value (NAV) had risen 4.7% to $12.1 billion. The business said it had $716 million of cash and liquid income funds available. I think that makes it well-placed to invest in any opportunities it sees during this market sell-off and whatever happens over the rest of 2025.